超出范围的索引不会在 Python 中引发 IndexError

Question

When used together with Booleans, the IndexError may not be raised.

For example, assume

list 1 = [1, 2, 3]

This will return True .

True or True and list1[3] > 3

But this will raise IndexError .

False or True and list1[3] > 3

Answer 1

The first line will read the True and not continue because there is an or so the list[3] > 3 doesn't matter and won't be evaluated, instead True is returned.

The second line starts with a False + or requiring it to read the next boolean expressions to return the output. It will read True and try to evaluate the list[3] > 3 expression which will raise the IndexError

Answer 2

This is because the nature of boolean operator
True or True and list1[3] > 3
since you have written this as True or some logic , as it encountered True and a trailing or it will simply ignore rest of the logic because a logic will always be True if it starts with True and there is a or in between but in case of and it could be False since True and False return False thus it will check for the rest of the logic. And your second one starts with False so False can be True if it is being followed by an or thus it checks for your rest of the logic where it encounters an error

Answer 3

Because index number is till 2. List indexes begin with 0. This will work:

Make your list name right first:

list1 = [1, 2, 3]

False or True and list1[2] > 3